There is a well-known stud bolt extending upwardly in a rod-like form, being threaded downwardly from the upper end to be welded to a base member such as a panel, for use in mounting a member to be attached on the base member. This stud bolt is frequently used to mount a decorative member or the like on, for example, a vehicle body since the decorative member can be attached to a clip, which is then mounted on a stud member attached to a base. The clip is mounted by forcing it over the stud and removed by rotation.
Automatic stud welding is a generally used method to weld a stud bolt to a vehicle body and in that work, studs have to be fed automatically one by one, with the welding end leading, to a welding gun. It sometimes occurs that the studs are not kept in their proper orientation in feeding which causes the gun to jam. Since the periphery of the stud is threaded, only a small electric contact surface exists between the collet and the stud. This limited contact area may not be sufficient for the high welding currents used, and also tends to produce electrolytic corrosion.